tapsite

tapsite

The MCP server for web intelligence extraction. 52 tools that give AI agents the ability to understand websites — not just drive a browser, but extract structured intelligence about design systems, accessibility, performance, content, and more.

Other MCP browser tools let agents click buttons. tapsite lets agents extract a complete color palette, audit WCAG contrast ratios, diff two sites' design tokens, or track accessibility regressions over time — all as structured JSON that agents can reason about.

Works with Claude, Cursor, Windsurf, and any MCP-compatible AI agent. LangChain/LangGraph integration coming soon.

View the full docs site →

Installation

# Quick start (no install required)
npx -y tapsite

# Or install globally
npm install -g tapsite
npx playwright install chromium
npx playwright install-deps chromium

Add to your AI agent's MCP config:

{
  "mcpServers": {
    "tapsite": {
      "command": "npx",
      "args": ["-y", "tapsite"]
    }
  }
}

First run: Playwright will install Chromium automatically if not already present (~150MB one-time download).

Also available on the MCP Registry and Glama.

What tapsite does

Extract design systems — colors, fonts, spacing scales, breakpoints, components, shadows, icons, CSS variables, and contrast ratios from any website. Output as structured JSON or W3C design tokens.

Audit quality — accessibility scoring with WCAG contrast analysis, performance timing (Core Web Vitals), tech stack detection, dark mode support, and animation inventory.

Compare and track — diff two sites side by side, or track a single site over time with snapshot-based temporal diffs. Regressions and improvements are flagged automatically.

Work behind login walls — persistent browser sessions with full MFA support. Log in once manually, then extract across tool calls without re-authenticating. Credentials never enter the chat.

Showcase

Tools (52)

Session (8)

Tool	Description
tapsite_login_manual	Open headed browser for manual login + MFA
tapsite_login_check	Verify authenticated session state
tapsite_inspect	Navigate to URL and inspect the DOM (nav, headings, buttons, forms, tables, links)
tapsite_screenshot	Take a screenshot of the current page
tapsite_interact	Click or fill an indexed element from the last inspect
tapsite_scroll	Scroll the page
tapsite_run_js	Execute arbitrary JavaScript and return the result
tapsite_close	Close the browser session

Content Extraction (5)

Tool	Description
tapsite_extract_table	Extract a specific table as structured data
tapsite_extract_links	Extract all links with text and href
tapsite_extract_metadata	Extract page metadata (title, description, OG tags, etc.)
tapsite_extract_content	Extract main readable content (article body, headings, paragraphs)
tapsite_extract_forms	Extract all forms with fields, labels, and actions

Design Tokens (5)

Tool	Description
tapsite_extract_colors	Extract color palette (hex values + usage counts)
tapsite_extract_fonts	Extract font families, sizes, weights
tapsite_extract_css_vars	Extract CSS custom properties
tapsite_extract_spacing	Extract spacing scale values
tapsite_extract_shadows	Extract box-shadow and text-shadow patterns

Visual Assets (4)

Tool	Description
tapsite_extract_images	Extract all images with src, alt, dimensions
tapsite_download_images	Download images to local output directory
tapsite_extract_svgs	Extract inline SVGs
tapsite_extract_favicon	Extract favicon URLs and sizes

Layout Intelligence (3)

Tool	Description
tapsite_extract_layout	Extract layout tree (inline text representation)
tapsite_extract_components	Detect repeated UI components and patterns
tapsite_extract_breakpoints	Extract responsive breakpoints from CSS media queries

Network Intelligence (3)

Tool	Description
tapsite_capture_network	Capture network requests during a page load
tapsite_extract_api_schema	Infer API schema from observed network traffic
tapsite_extract_stack	Detect frontend framework, libraries, and tech stack

Multi-page (2)

Tool	Description
tapsite_crawl	Crawl multiple pages from a start URL
tapsite_diff_pages	Compare two URLs (cross-site) or track changes over time (temporal) using real extractors

Advanced (16)

Tool	Description
tapsite_extract_animations	Extract CSS animations and transitions
tapsite_extract_a11y	Accessibility audit (ARIA, roles, contrast issues)
tapsite_extract_darkmode	Detect dark mode support and extract dark palette
tapsite_extract_perf	Extract performance metrics (Core Web Vitals, resource sizes)
tapsite_extract_icons	Detect icon libraries and extract icon usage
tapsite_extract_contrast	Audit WCAG contrast ratios between text and background
tapsite_extract_security	Audit security headers (CSP, HSTS, SRI, permissions policy)
tapsite_extract_pwa	Detect PWA support (manifest, service worker, installability)
tapsite_extract_i18n	Extract internationalization signals (lang, hreflang, translations)
tapsite_extract_graphql	Detect GraphQL endpoints and introspect schemas
tapsite_extract_aiml	Detect AI/ML integrations (models, embeddings, inference endpoints)
tapsite_extract_canvas	Extract canvas and WebGL usage patterns
tapsite_extract_wasm	Detect WebAssembly modules and usage
tapsite_extract_web_components	Detect custom elements and shadow DOM usage
tapsite_extract_third_party	Inventory third-party scripts, trackers, and services
tapsite_extract_storage	Audit client-side storage (cookies, localStorage, sessionStorage, IndexedDB)

Export (2)

Tool	Description
tapsite_export	Export inspection results as JSON + Markdown + HTML report + CSV tables + screenshots
tapsite_export_design_report	Full design system report: report.html (visual), design-tokens.json (W3C format), design-tokens.css (copy-pasteable :root vars)

Workflows (4)

Tool	Description
tapsite_teardown	Comprehensive competitive design teardown (all extractors)
tapsite_audit	Pre-launch quality audit (a11y, contrast, perf, SEO, darkmode)
tapsite_harvest	Inventory all site assets (images, SVGs, forms, fonts, links)
tapsite_designsystem	Extract design tokens as W3C JSON and CSS variables

LangChain / LangGraph integration (coming soon)

Native LangChain and LangGraph integration is on the roadmap. When released, it will provide a dedicated Python wrapper with tool subsets and managed session lifecycle.

Security

Prompt injection defense

When extracting content from untrusted web pages, tapsite applies two layers of protection:

• Hidden element filtering — Extractors skip elements with display:none, visibility:hidden, opacity:0, zero-size, and clip-hidden styling. This prevents invisible text (a common prompt injection vector) from entering extraction results.

• Output sanitization — All text returned to the LLM is scanned for prompt injection patterns: instruction overrides, role hijacking, exfiltration attempts, and tool manipulation. Matches are flagged inline as [INJECTION_DETECTED] rather than silently dropped.

Credential safety

Never pass credentials through the chat. Use tapsite_login_manual to open a headed browser, log in manually (including MFA), then tapsite_login_check to confirm. Credentials never touch the AI provider's servers or local transcripts.

Docker

tapsite ships a Dockerfile and docker-compose.yml for headless-only use — CI pipelines, server deployments, or anywhere you don't want a local Node.js install.

docker build -t tapsite .
docker compose up

tapsite_login_manual is not available in Docker (it requires a display). To use authenticated sessions in Docker, log in locally first, then mount the profiles/ directory into the container:

volumes:
  - ./output:/app/output
  - ./profiles:/app/profiles

Security note: profiles/ contains live session cookies. Don't commit it to version control (it's already in .gitignore).

Development setup

git clone https://github.com/mgriffen/tapsite
cd tapsite
npm install
npx playwright install chromium
npx playwright install-deps chromium

MCP config pointing to local source:

{
  "mcpServers": {
    "tapsite": {
      "command": "node",
      "args": ["/absolute/path/to/tapsite/src/server.js"]
    }
  }
}

Project structure

src/
  server.js        — MCP server entry point
  browser.js       — shared Chromium context (ensureBrowser, closeBrowser)
  helpers.js       — shared helpers (navigateIfNeeded, summarizeResult, indexPage)
  sanitizer.js     — prompt injection detection
  diff.js          — per-extractor diff logic and extractor name/args mapping
  snapshots.js     — temporal snapshot I/O (saveSnapshot, loadLatestSnapshot)
  extractors.js    — browser-context extraction functions (page.evaluate())
  exporter.js      — file export: JSON, Markdown, HTML, CSV
  inspector.js     — DOM extraction for inspect tools
  cli.js           — standalone CLI (login, inspect, session)
  config.js        — paths and defaults
  tools/
    session.js     — login, inspect, screenshot, interact, scroll, run_js, close
    extraction.js  — all extract_* tools
    network.js     — capture_network, extract_api_schema, extract_stack
    multipage.js   — crawl, diff_pages
    export.js      — export, export_design_report
    workflows.js   — teardown, audit, harvest, designsystem
profiles/          — browser state / session cookies (gitignored)
output/            — export results + snapshots (gitignored)

Output formats

• output/run-{timestamp}/ — tapsite_export: JSON, Markdown, HTML, screenshots, CSV tables
• output/design-report-{timestamp}/ — tapsite_export_design_report: report.html, design-tokens.json, design-tokens.css
• output/snapshots/{domain}/ — tapsite_diff_pages temporal snapshots

License

MIT